Spinel Mineral

A Spinel Mineral is a mineral that belongs to the spinel group and crystallizes in the cubic crystal system.

• Context:
  • It can occur as the magnesium/aluminium member of the spinel group with the formula MgAl₂O₄.
  • It can form pointed, octahedral crystals, leading to its name derived from the Latin "spina" (meaning spine).
  • It can range in color from colorless to vibrant shades such as red, blue, green, and violet due to trace element substitutions.
  • It can be found in metamorphic rocks, in association with limestone and dolomite, as well as in placer deposits.
  • It can exhibit high refractive indices and hardness (7.5–8 on the Mohs scale), making it suitable for use as a gemstone.
  • It can serve as a geochemical indicator in petrological studies due to its stability under varying pressure and temperature conditions.
  • It can include natural and synthetic variants, with synthetic spinels often used in industrial applications.
  • ...
• Example(s):
  • Red Spinel, which is known for its vivid red color often mistaken for ruby.
  • Blue Spinel, which is prized for its rare cobalt-colored hues.
  • Synthetic Spinel, which is used in optical materials and as durable coatings in technology.
  • Hercegovinaite, a manganese-dominant spinel variety.
  • ...
• Counter-Example(s):
  • Garnets, which lack a cubic crystal structure but may also be used as gemstones.
  • Corundums, which have a different chemical composition and crystal structure but share some gemstone qualities.
  • Peridots, which are also magnesium-rich minerals but belong to the olivine group.
• See: Cubic Crystal System, Oxide Minerals, Spinel Group, H–M Symbol, Magnesium, Aluminium.

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References

2024

• (Wikipedia, 2024) ⇒ https://en.wikipedia.org/wiki/Spinel Retrieved:2024-12-15.
  • Spinel ( ) is the magnesium/aluminium member of the larger spinel group of minerals. It has the formula in the cubic crystal system. Its name comes from the Latin word , a diminutive form of spine, in reference to its pointed crystals.

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